Bishydrobis(tetrazol-1-yl)borate (BTB) based energetic ionic liquids with high density and energy capacity as hypergolic fuels

A new family of bishydrobis(tetrazol-1-yl)borate (BTB) based energetic ionic liquids were synthesized by a straightforward N-hydroboration of tetrazole followed by an ionic metathesis. The BTB-based ionic liquids are hypergolic with oxidizers and show superior energy capacity with high positive HOF (often ≥2.0 kJ g−1), high density (≥1.2 g cm−3), high density impulse (often ≥367 s g cm−3) and short ignition delay times (